Flexible door for building closures



Aug. 27, 1968 R. L. KUSS 3,398,779

FLEXIBLE DOOR FOR BUILDING CLOSURES 2 Sheets-Sheet 1 Filed Dec. 21, 1966 INVENTOR: gram L.Krss.

FIE-3- Aug. 27, 1968 R. L. KUSS FLEXIBLE DOOR FOR BUILDING CLOSURES 2 Sheets-Sheet 2 Filed Dec. 21, 1966 INVENTORZ RALPH L.

ATTYE.

United States Patent 3,398,779 FLEXIBLE DOOR FOR BUILDING CLOSURES Ralph L. Kuss, Findlay, Ohio, assignor to R. I. Kuss & C0,, Inc., Findlay, Ohio, a corporation of Ohio Filed Dec. 21, 1966, Ser. No. 603,598 Claims. (Cl. 160-243) ABSTRACT OF THE DISCLOSURE This invention relates to an improved flexible door for large building closures, such as aircraft hangars, gymnasiums or the like. More specifically, this invention relates to a flexible closure of the type which includes a flexible membrane secured to an overhead building member with a roller secured to the membrane whereby rotation of said roller will open and close the door.

In order to eliminate the need for long flexible electrical connections or exposed current conducting tracks, the invention herein provides a flexible door of the type described in which the prime mover remains in a fixed position and the door is driven in a vertical path by an endless power transmitting member which transfers power from the prime mover to the roller of the door to apply a rotational force to the roller and also a vertical force component in the direction of the movement of the roller.

Background of the invention (1) Field of invention-The need for improved, quickacting, lightweight and inexpensive closures for large openings has become critical due to recent developments in aviation and other aerospace activity which requires the rapid opening of large hangars or sheds for easy egress and ingress of equipment. While foldingor accordion-type doors have been commonly used in aircraft hangars for years, they have certain disadvantages because they are diflicult for a single person to operate, they cannot be closed with any speed, and they require a substantial amount of storage space for the folded door portions when the door is open. Due to recent developments in flexible fabrics, such as nylon, dacron, etc., it has been possible to fabricate large doors which basically include a flexible curtain secured at its top to an overhead member and a roller secured generally at the bottom of the curtain with a means for raising and lowering the door by winding or unwinding it upon the roller. Such doors, if properly constructed, have the requisite strength to withstand wind forces and are advantageous in that the door, when in its upper, rolled position, requires relatively little storage space. Other advantages are that through use of certain types of fabric, the outside light may be permitted within the hangars or building space, and because the doors are not entirely rigid, accidental brushings by airplane wings or other equipment do not harm the door or the equipment.

(2) Description 0 the prior art.United States Patent 3,211,211 discloses a flexible door of this general type in which the motive power for raising and lowering the door includes an electrically powered motor which, through an appropriate reduction gear, applies a torque to the roller which causes it to wind or unwind itself within the fabric. While doors of this general nature have been satisfactory in many respects, in large installations it has been difficult and costly to provide the necessary structure and electrical leads required for the motor to travel up and down along with the roller.

Summary of the invention The invention provides a flexible closure including a flexible membrane or sheet having one edge secured to a fixed building member and an opposite edge secured to a roller whose rotation will open or close the closure. The means for moving the roller includes a fixed prime mover mechanically coupled to the roller to apply both a rotational and a vertical force component thereto with the vertical force component in the same direction as the direction of movement of the roller.

It is an object of this invention to provide a flexible door or closure of the type described in which the prime mover remains stationary and which, if the power transmittin g linkage between the prime mover and the flexible membrane roller is damaged or breaks, the roller will remain in any elevated position and will not fall to the bottom of the closure.

It is another object of this invention to provide a flexible door of the type described which may be selectively opened or closed by means of a driven prime mover, or in the event of an emergency, may be manually opened or closed by hand from either side of the closure.

Other objects and advantages of this invention will be apparent to those skilled in the art.

Brief description of the drawing FIG. 1 is a view in perspective of a preferred embodiment of the flexible door of this invention, as it is seen from the inside of a building, such as an aircraft hangar and showing the door in partially open position;

FIG. 2 is a cross-sectional view, taken along line 2-2 of FIG. 1, and showing, on an enlarged scale, the method in which the flexible membrane is attached to the overhead building member;

FIG. 3 is a cross-sectional view, taken along line 33 of FIG. 1, and showing, on an enlarged scale, the details of the guide track at one end of the roller and of a inechanism for locking the door in closed position;

FIG. 4 is a cross-sectional view, taken along line 4-4 of FIG. 1, and showing, on an enlarged scale, the details of the drive mechanism for the door roller;

FIG. 5 is a partial cross-sectional view, taken along line 55 of FIG. 1, and showing, on an enlarged scale, additional details of the drive mechanism of the door roller;

FIG. 6 is a partial view in elevation showing the drive mechanism at one end of the roller as it would be seen from the position indicated by line 66 of FIG. 1, and

FIG. 7 is a cross-sectional view in elevation, taken along line 77 of FIG. 1, and showing, on an enlarged scale, the details of a lock mechanism at the end of the roller for holding the roller in its lowermost position.

Description of a preferred embodiment Referring first to FIG. 1, the flexible door generally consists of a flexible membrane or sheet 10 secured to its uppermost edge to a horizontal building member or lintel 11 in a manner which will be subsequently explained. The lowermost edge of the membrane 10 is secured to a large roller 12, which may be solid or tubular, such that when the roller 12 is rotated, it will roll itself upon or unwind itself from the membrane 10 and thus move up or down between the lowermost position at the floor 13 of the building or at an uppermost position adjacent the lintel 11. The details of the manner of securing the membrane 10 to the roller 12 and of the fabrication of the membrane 10 are not considered to be a part of this invention.

On each end of the roller 12 is a guide track for guiding the roller in a vertical plane as it moves up and down upon the membrane 10'. Referring to FIGS. 1 and 3, the guide track at the left hand end of the door, as seen in FIG. 1, includes a guide rail 14 which extends vertically alongside the path of the left hand end of the roller and is held parallel to the axis of the roller by an angle iron secured to the vertical building support or the building wall, designated by reference numeral 16 in FIG. 3. An end plate 17 is positioned adjacent the end of the roller 12 and holds a pair of rolling guides 18 and 19 on either side of the guide rail 14. A second pair of rolling guides (not shown) is positioned below guides 18 and 19 shown in FIG. 3.

As shown in FIG. 3, the roller 12 is of a tubular construction and has, at its left end, a core pin 20 welded to radial webs 21 and 22 and extending beyond the end of the tubular roller 12 through an aperture 23 in the end plate 17. Between the end plate 17, which does not rotate, and the core pin 20 is a suitable bearing, designated by reference numeral 24 so that the core pin 20 and tubular roller 12 can freely rotate relative to the end plate 17. A collar 25 is secured to the core pin 20 to the left of the end plate 17 to limit axial movement of the roller 12 relative to the end plate 17 As seen in FIG. 3, the outside of the building is at the top. To reduce air flow into or out of the building, an elongate sealing member 26 may be provided to close this space. The sealing member 26 may be slightly tapered, increasing in width in a downward direction to accommodate changes in the effective diameter of the roller 12 as turns of the membrane 10 are built up or taken oif the roller 12.

Referring to FIGS. 1 and 5, the right hand end of the roller, as seen in FIG. 1, has a similar guide track or rail 27 held adjacent the vertical path of the roller by an angle iron 28 secured to the inner side of the building wall 29 on the other side of the opening. An end plate 30 supports a pair of rolling guides 31 and 32 on each side of the guide rail 27. As seen in FIG. 4, a second pair of rolling guides 33 and 34 are positioned on a lower corner of the end plate 30 on either side of the rail guide 27 to prevent rotation of the end plate 30 relative to the guide rail 27.

A central drive shaft 35 is axially positioned within the tubular roller 12 by a pair of radial webs 36 and 3-7 and the shaft 35 extends through a bearing 38 positioned within an aperture in the end plate 30 so that the shaft end is exposed on the right hand side of the end plate 30, as viewed in FIG. 5. As thus far described, the guide mechanisms on either end of the roller 12 are essentially similar.

As best seen in FIG. 4, a toothed worm wheel 39 is secured to the exposed end of the drive shaft 35. Above the worm wheel 39, an engaging worm 40 is secured to the end plate 30 by a pair of bearings 41 and 42 which journal a worm shaft 43 having one end extending beyond the edge of the end plate 30. Secured to this outer end of the worm shaft 43 is a chain drive sprocket 44 which is positioned beyond the outermost edges of the roller 12, as seen in FIGS. 1 and 5. Above and below the drive sprocket 44 is a smaller sprocket or crowder 45 and 46 journaled for rotation on a stub shaft secured to the end plate 30 as indicated by reference numerals 47 and 48. As seen in FIG. 4, the chain crowders 45 and 46 and the drive sprocket 44 lie in a common vertical plane and have their axes of rotation parallel but not in vertical alignment, as best seen in FIG. 6. As thus so far described, it will be seen that rotation of the drive sprocket 44 will turn the worm shaft 43 and thus the worm 40 which is engaged with the teeth of the worm wheel 39. Thus rotation of the drive sprocket 44 will turn the worm wheel 39, the drive shaft 35 and the tubular roller 12, causing the roller 12 to wind or unwind itself from the membrane 10, depending upon the direction of rotation. The proper relationship of the direction of rotation of the drive sprocket 44 to the direction of rotation of the roller 12 is important for proper operation of the door, as will be subsequently explained.

Referring again to FIG. 1, a pair of chain guide sprockets 49 and 50 are positioned in a vertical plane passing through the drive sprocket 44 at the uppermost and lowermost extremities of movement of the roller 12. The guide sprocket 50 is journaled upon a short shaft which is held in part by a plate 51 while the guide sprocket 49 is secured to a shaft 52 extending generally horizontally in a direction normal to the plane of the membrane. An electric motor M is supported by a horizontal cross members 53 secured to an upper portion of the angle iron 28. The driving shaft 54 of the motor M is coupled to the shaft 52 by a suitable clutch 55. The shaft 52 is journaled at the other end by a bearing 56 and may extend through this bearing to the outside of the closure, as will be subsequently explained and as is indicated in dotted line in FIG. 1.

An endless chain 57 extends around the guide sprockets 49 and 50, as shown in FIG. 1 and engages the chain crowding sprockets 45 and 46 and the drive sprocket 44 in the manner shown best in FIGS. 1 and 6. Referring to FIG. 6, the chain extends around the crowder 45, is engaged with a substantial portion of the periphery and teeth of the drive sprocket 44 and returns to its vertical path around the crowder sprocket 46. The use of these crowder sprockets 45 and 46 assures that the chain 57 at all times will remain in contact with the teeth of the drive sprocket 44 throughout movement of the roller 12 and its associated mechanism up and down over the vertical extent of the chain path. As thus far desscribed, it will be seen that rotation of the shaft 52 by the motor M will turn the chain guide sprocket 49 and drive the chain 57. The chain 57 in turn Will drive the drive sprocket 44, whose rotation, as previously explained, turns the worm 40, the worm wheel 39 and thus the roller 12. As the roller 12 is turned, it will wind or unwind itself upon the membrane 10, causing the mechanism carriage, comprising the end plate 30 and associate parts, to move upwardly or downwardly with the roller 12.

The mechanism previously described has the advantage that, due to the mechanical advantage derived through use of the worm 40 and worm wheel 39, a relatively high speed motor M may be used to drive the roller 12 at a relatively low speed. This speed decrease is accomplished essentially by the worm gearing which has the additional advantage that, along with the speed decrease, an increase in torque is imparted which enables the use of a relatively small motor even for starting loads.

As previously stated, the flexible door of this construction is inherently safer than doors of the prior art constructions in that it is self-supporting and will remain in any opened position even if the power should fail or if the chain 57 should part. Because of the high torque increase through the worm 40 and worm wheel 39 from the motor to the roller 12, a very large torque in the opposite direction, placed upon the worm wheel 39, will not turn the worm 40. Thus the worm 40, unless driven by the motor M, acts as a brake upon the Worm wheel 39 and further movement of the roller 12 or door itself. This self-locking feature is advantageous not only as a safety feature but as a means for holding the door in any partially open position for various purposes, such as to partially vent the building, admit low loads while conserving heat within the building, etc.

As previously stated, the direction of rotation of the drive sprocket 44 and thus the proper vertical direction of movement of the engaging chain 57 relative to the direction of roller 12 movement are important aspects of the invention. With the chain 57 directed around the drive sprocket 44 as illustrated in FIGS. 1 and 6, the worm 40 must have a left hand thread or pitch, as illustrated in FIG. 4. Consequently, the upward movement of the portion of the chain 57 engaging the drive sprocket 44 (hereinafter called the drive section 57a), will, through the left hand threaded worm 40, turn the worm wheel 39 in a clockwise direction, as seen in FIG. 4, causing the roller 12 to roll itself upon the membrane 10 and to rise. Thus the upward movement of the drive section 57a of the chain 57 will be accompanied by the upward movement of the roller 12, its carriage, and drive sprocket 44 so that there is less relative velocity between the chain and these parts and consequently less tendency to place dangerous forces upon the worm shaft 43, the end plate 30, etc. More importantly, however, is the fact that the drive section 57a, in moving upwardly to raise the roller 12, counteracts a twisting moment imparted to the carriage by the weight of the roller. Referring to FIG, 4, with the mechanism at rest, the combined weight of the roller 12 and turns of flexible sheet wrapped thereon, as they are suspended by the remainder of the sheet 10 secured to the building lintel 11, tend to urge the roller 12 and thus the worm wheel 39 in a counterclockwise direction. This counterclockwise moment is prevented by the worm 40 which engages the worm wheel 39 at a position vertically between the pairs of rolling guides 31, 32 and 33, 34 positioned along the guide rail 27. The rolling guides 31 and 33 are pushed with considerable force against the guide rail 27, in the direction shown by arrows F and F to resist a twisting movement of the entire carriage by the force exerted upon the worm 40. To at least partially counteract this twisting moment applied to the carriage, the upward movement of the drive section 57a of the chain 57 causes an upward force, designated by arrow F to be applied to the carriage through the drive sprocket 44 and worm 40, which reduces the force with which the rolling guides 31 and 33 are pressed against the guide rail 27. Conversely, if the mechanism were so arranged such that the downward movement of the drive section 570 of the chain 57 caused upward movement of the roller, the vertical chain force (opposite in direction to arrow F in FIG. 4) would further increase the twisting moment on the carriage and would push the rollers 31 and 33 against the rail 27 with forces of increased magnitude, thus interfering with or preventing operation of the mechanism.

It should be recognized that the worm 40 could have a right hand thread or pitch if the drive section 57:: of the chain 57 were engaged with the opposite sector (the right hand sector in FIG. 6) of the drive sprocket 44. This combination would also give the desired relationship of the upward movement of the drive section 57a causing the upward movement of the roller 12.

The motor M is preferably a reversible motor so that the door may be raised and lowered by manipulation of a suitably connected electrical switch. As previously stated, the shaft 52 connected to the drive shaft 54 of the motor M by the clutch 55 may extend through the building wall 29 and be provided with a hand wheel or manually operated chain fall (not shown), for manual operation of the door from outside the building. Additionally, should power fail, the mechanical advantage provided to this system through use of the worm gearing is such that the door may be operated from within the building by pulling the chain 57 itself. Thus the door may be raised by pulling downwardly upon the other vertical bight of the chain which is not associated with the drive sprocket 44 to move the drive section 57a upwardly.

In another embodiment, in place of the chain 57, a suitable endless nylon rope could be used in the same manner with pulleys substituted for the sprockets 44, 49, 50, and crowders 45, 46, in a manner apparent to those skilled in the art.

In addition to the features hereinbefore described, the preferred embodiment of this invention includes a mechanism for locking the roller 12 and door in its lowermost, closed position which includes means for interfering with the upward movement of the shafts and 35. When these shafts 20 and are prevented from moving upwardly with the rotation of the roller 12, a slight amount of torque placed on the roller 12 will tighten the membrane 10 for complete closure of the opening and the membrane 10 will be held taut due to the locking action of the worm 40 against the worm wheel 39 as previously explained.

Referring to FIGS. 1, 3, and 7, a shaft detent 58, best seen in FIG. 7, is pivotally mounted upon a vertical structural member, such as the plate 51. The detent 58 is positioned such that its end will strike the core pin 20 or the drive shaft 35 as these shafts move in a vertical path. As seen in FIG. 7, the detent 58 is biased by a spring 59 to its forward position in the line of movement of the core pin 20 or shaft 35 or in its rearward position indicated by dotted line, clear of the path of movement of the shaft 35. Because the spring 59 moves across the pivot axis of the detent 58, it will hold the detent 58 in either position. As is apparent from FIG. 7, movement of the shaft 35 to its lowermost position will rock the detent 58 in a counterclockwise direction, permitting the shaft 35 to pass. However, shaft movement in an upward direction will be stopped by the stub end 60 of the detent 58. The upper end of the detent 58 is provided with a handle 61 which extends through the building wall 29 so that the door may be unlocked from outside of the building. Another suitable handle or unlatching means 62 is provided for unlocking the door from inside of the building. Thus the door, when fully lowered, will automatically lock itself in closed position and may be unlocked from either inside or outside of the building. It is to be noted that the locking detents 58 do not contact the roller 12 itself or the outermost wrap of the flexible membrane 10 thereupon which could be injured by repeated rubbing.

In addition to the detents 58 locking the roller 12 in lowermost position on each end, a separate clamp mechanism, generally indicated by reference numeral 63 may be provided to engage the mid-portion of the roller 12 and membrane 10 when in its lowermost position. This clamp 63, the details of which are not shown or described, may be manually locked or unlocked from either inside or outside of the building.

FIG. 2 shows a preferred method for attaching the membrane 10 to the horizontal lintel member of the building. Secured to the inner surface of the lintel 11 is an extruded channel 64 which extends substantially across the door opening. A tubular rod 65 extends across the top of the membrane through a pocket sewn in a single hem at the upper edge of the membrane, as seen in FIG. 2. A plurality of locking lugs 66, whose cross section is shown in FIG. 2 are positioned at spaced apart intervals along the channel 64 with the tubular rod 65 and the hem of the membrane 10 placed in the lowermost position of the channel 64. A locking l-ug 66 is inserted by placing its uppermost pivot ball 67 in the upper portion of the channel 64 and rotating the lug 66 in a clockwise direction, as shown in FIG. 2, until its locking portion 68 rests above the position of the rod 65 with a locking rib 69 positioned inwardly of the center of the rod 65. When so positioned, an upward force upon the rod 65 caused by a downward pull on the membrane 10, will further lock the lug 66 within the channel 64. Thus while the locking lugs 66 and the channel 64 may be easily engaged with one another, extreme forces exerted upon the membrane 10 by the weight of the roller 12 and wind loads, etc. will not cause them to part. Also, because the locking lugs 66 are relatively small, they may be hand manipulated and inserted at any portion or in any number upon the channel 64 which is securely bolted to the building lintel 11.

Finally, as an additional safety feature, limit switches can be positioned at the extreme upper and lower ends of the path of movement of the roller 12 to assure that roller movement is stopped. Such switches (not shown) would be normally closed switches having a toggle extending into the path of a moving portion of the carriage 32 such that they would be opened when the car- 'riage reaches its extreme upper or lower position to open the power circuit to the motor M.

Other advantages of the above described preferred embodiment of this invention may be made by persons skilled in the art Without departing from the scope and spirit of the attached claims.

I claim:

1. In a flexible closure device for building openings including a flexible membrane secured at its upper edge to a substantially horizontal building member above such opening and having a substantially horizontal roller extending across said opening and secured to said membrane whereby rotation of said roller will raise said roller as it winds said membrane thereupon, the improvement comprising, in combination, a toothed worm wheel coaxially secured to one end of said roller, a vertically extending track adjacent one end of said roller and extending between its uppermost and lowermost positions, a movable carriage member slidably guided. by said track and rotatably attached to said roller for vertical movement therewith, a worm journaled upon said movable carriage and engaged with said toothed worm wheel whereby movement of said roller and worm requires rotation of said worm and whereby rotation of said worm will turn said worrn wheel and roller to wind said membrane upon said roller, a drive sprocket secured to said worm and means including a vertically extending chain drive coacting with said drive sprocket whereby, when said chain is driven in an upward direction, said drive sprocket and worm and worm wheel will rotate to cause said carriage and said roller to rise as said roller winds said membrane upon itself.

2. The device of claim 1 wherein said chain drive includes an endless chain extending parallel to said track and directed about chain guide sprockets rotatably secured at the upper and at the lower ends of said track, and externally actuated drive means engaged with said chain to drive it around said guide sprockets, whereby said drive sprocket and thus said roller are rotated by said driven chain.

3. The device of claim 2 wherein said chain is engaged by said drive sprocket between a pair of chain crowding devices journaled for rotation on said carriage and acting to maintain said chain in engagement with said drive sprocket throughout a substantial portion of its periphery.

4. The device of claim 2 wherein the upward movement of the drive portion of said endless chain extending to and in contact with said drive sprocket causes said worm wheel to turn said roller in a first direction to wind said membrane upon said roller and wherein the downward movement of said drive portion of said dhain causes said worm wheel to turn said roller in a second direction to unwind said membrane from said roller.

5. The device of claim 2 wherein said externally actuated drive means includes a reversible motor having a drive shaft operatively connected to one of said chain guide sprockets whereby rotation of said motor drive shaft in either direction will drive said chain guide sprocket and thus said chain in either direction.

6. The device of claim 2 in which one of said chain guide sprockets is secured to a rotatable shaft extending away from said guide sprocket and which further includes means secured to said shaft for manually rotating said shaft and said guide sprocket to manually drive said chain in either direction.

7. The device of claim 6 wherein said rotatable shaft extends generally normal to the plane of said membrane and wherein said manual drive means is positioned on the opposite side of said membrane from said guide sprockets and said endless chain. 8. A drive mechanism for raising and lowering a vertical closure member having a vertically hung flexible sheet with a generally horizontal roller secured thereto whereby rotation of said roller in a first direction will cause said roller to move upwardly as it Winds itself wit-bin said sheet and whereby rotation in a second direction will cause said roller to move downwardly as it unwinds itself from said sheet, said mechanism comprising;

a movable carriage member adjacent one end of said roller and adapted for vertical movement therewith, toothed worm wheel coaxially secured to said one end of said roller and positioned within said movable carriage, worm journaled within said movable carriage and engaged with said toothed worm wheel whereby rotation of said worm will turn said toothed worm wheel,

drive means for turning said worm in either direction whereby as said roller is wound or unwound upon said sheet, said roller and said carriage will move upwardly or downwardly, respectively and whereby, when said drive means is disengaged from said worm, said roller and said carriage will be supported by said sheet wound upon said roller,

said drive means including a vertically extending drive member coupled to said worrn such that movement of said drive member in an upward direction will cause said roller to rotate in said first direction and such that movement of said drive member downwardly will cause said roller to move in said second direction.

9. The drive mechanism of claim 8 wherein said drive member includes an endless drive chain extending vertically alongside the vertical path of said carriage around chain guide sprockets rotatably secured at the upper and lower ends of said path,

a drive sprocket secured to said worm and engaged with said drive chain,

and externally actuated means engaging said drive chain to drive it around said guide sprockets whereby said drive sprocket and said worm are rotated by movement of said chain.

10. The drive mechanism of claim 9 wherein one of said guide sprockets is secured to a rotatable shaft extending generally normal to the plane of said membrane and terminating on each side of said plane whereby said shaft may be turned from a position on either side of said door.

References Cited UNITED STATES PATENTS DAVID J. WILLIAMOWSKY, Primary Examiner. P. M. CAUN, Assistant Examiner. 

